The present invention relates to clamps used to connect tubes and, in particular, flared or flanged tubes.
Clamps are often used to connect tubes. For example, most vehicles incorporate several tubes in their exhaust system that are connected by clamps. Tubes from the engine block, the catalytic converter and the tail pipe are connected to one another by clamps. The clamps and tubes are exposed to a wide range of temperature variations and stresses. The temperature varies from ambient, at vehicle start-up, to near exhaust gas temperature when operating under heavy loads. Stresses arise from engine vibrations, exhaust gas pressure, exhaust system weight, road bumps, etc.
The temperature variations often cause expansion and contraction of both the tubes and the clamps. The clamps must securely connect the tubes to prevent leakage while withstanding the temperature variations and stresses. As shown in FIG. 1, clamps 10 of the prior art consist of a collar 12 that have two lugs 14 of uniform thickness extending from ends of the collar. Apertures are formed within the lugs, and a fastener 16 is inserted through the apertures to connect the lugs 14. The collar 12 is positioned around and tightened onto the tubes to be connected. Specifically, the fastener is tightened sufficiently to seal the connection.
When tightening the clamp 10 of the prior art, both lugs 14 may bend towards one another. The clamps can only be effectively tightened to a point where the portion of the lugs 14 near the bolt touch and press against one another. In this case, some portion of the installation energy was wasted in deforming the lugs, instead of pulling both ends of the collar 12 together. Thus, the clamp often times does not generate enough force to seal the connection. Tubes to be connected, nonetheless, often require a tighter fit to prevent unwanted leakage. At installation, the collar 12 of the clamp 10 of the prior art must be opened to slide the clamp over tubes, including those that are flared or flanged. The collar 12 is often times too rigid to be sufficiently opened.
Accordingly, there exists a need for a clamp that addresses the shortcomings of the prior art.